Merge pull request #1854 from Rob--W/panel-show-at-DOMContentLoaded

Bug 1128478 - sdk/panel's show/hide events not emitted if contentScriptWhen != 'ready' r=erikvold

lib/sdk/panel.js

@@ -295,6 +295,9 @@ let hides = filter(panelEvents, ({type}) => type === "popuphidden");
 let ready = filter(panelEvents, ({type, target}) =>
   getAttachEventType(modelFor(panelFor(target))) === type);
 
+// Panel event emitted when the contents of the panel has been loaded.
+let readyToShow = filter(panelEvents, ({type}) => type === "DOMContentLoaded");
+
 // Styles should be always added as soon as possible, and doesn't makes them
 // depends on `contentScriptWhen`
 let start = filter(panelEvents, ({type}) => type === "document-element-inserted");
@@ -317,6 +320,10 @@ on(ready, "data", ({target}) => {
   let window = domPanel.getContentDocument(target).defaultView;
 
   workerFor(panel).attach(window);
+});
+
+on(readyToShow, "data", ({target}) => {
+  let panel = panelFor(target);
 
   if (!modelFor(panel).ready) {
     modelFor(panel).ready = true;

test/test-panel.js

@@ -1297,7 +1297,6 @@ exports["test panel addon global object"] = function*(assert) {
 exports["test panel load doesn't show"] = function*(assert) {
   let loader = Loader(module);
 
-  let showCount = 0;
   let panel = loader.require("sdk/panel").Panel({
     contentScript: "addEventListener('load', function(event) { self.postMessage('load'); });",
     contentScriptWhen: "start",
@@ -1335,6 +1334,24 @@ exports["test panel load doesn't show"] = function*(assert) {
   loader.unload();
 }
 
+exports["test Panel without contentURL and contentScriptWhen=start should show"] = function*(assert) {
+  let loader = Loader(module);
+
+  let panel = loader.require("sdk/panel").Panel({
+    contentScriptWhen: "start",
+    // No contentURL, the bug only shows up when contentURL is not explicitly set.
+  });
+
+  yield new Promise(resolve => {
+    panel.once("show", resolve);
+    panel.show();
+  });
+
+  assert.pass("Received show event");
+
+  loader.unload();
+}
+
 if (packaging.isNative) {
   module.exports = {
     "test skip on jpm": (assert) => assert.pass("skipping this file with jpm")